Retired tennis great Martina Hingis is being accused of adultery by her estranged husband, according to a report. (Fadi Al-Assaad/Reuters/Files)

The estranged husband of retired tennis star Martina Hingis is going public with accusations that she cheated on him twice during their marriage.

Hingis, set to be inducted into the International Tennis Hall of Fame this weekend in Newport, R.I., married Thibault Hutin, a French equestrian show jumper, in December 2010.

A year later, Hutin claimed he walked in on her with another man, according to the London Evening Standard.

"A year after the wedding [...] we were supposed to meet in New York and I wanted to give her a surprise," the 26-year-old told Swiss newspaper SonntagsBlick. "Upon arriving at the hotel room it was me that was surprised, because Martina was not alone."

Hutin said he forgave her and tried to salvage the marriage, only to find out that Hingis cheated on him again late last year.

"Martina has a very personal conception of morality," he said. "She has always been like that; I think she has always been unfaithful to her boyfriends."

Hingis, 32, was engaged to Swiss attorney Andreas Bieri before the pair went their separate ways prior to her meeting Hutin in April 2010 at a show-jumping competition in St. Tropez.

"She is not alone in the tennis world, which I now know quite well," he added. "But I thought she was different from the others, that she really loved me."

Hutin wasn't even aware that they had officially split up until Hingis told Swiss magazine Schweizer Illustrierten Monday that she had been separated since the beginning of the year.

Hingis is reportedly dating Spanish sports management executive David Tosas Ros. The pair was spotted sitting together at the French Open.

Hingis won five Grand Slam singles titles before taking time off in 2002 due to ankle injuries. She returned in 2006, only to retire for good in November 2007 after testing positive for cocaine at Wimbledon.